How To Do Oauth-requiring Operations In A Gae Cron Job?

This post is a followup to How to do OAuth-requiring operations in a GAE Task Queue?. As suggested by bossylobster in this post, I did try to hardcode the user_id in my script, but

Solution 1:

How is cron supposed to bypass that?

Make sure the cron url is configured with login: admin and not login: required. Cron jobs "get past the login prompt" automatically. See the documentation for more information.

How can I debug what's going on?

Since a cron job is started by a GET request to a specific url, you should be able to debug the job by just making a GET request to that url and either see what errors the development server makes or see what is in the logs for the GET request.